This invention relates generally to devices that produce ozone and an electro-kinetic flow of air from which particulate matter has been substantially removed, and more particularly to cleaning the wire or wire-like electrodes present in such devices.
The use of an electric motor to rotate a fan blade to create an air flow has long been known in the art. Unfortunately, such fans produce substantial noise, and can present a hazard to children who can be tempted to poke a finger or a pencil into the moving fan blade. Although such fans can produce substantial air flow, e.g., 1,000 ft3/minute or more, substantial electrical power is required to operate the motor, and essentially no conditioning of the flowing air occurs.
It is known to provide such fans with a HEPA-compliant filter element to remove particulate matter larger than perhaps 0.3 xcexcm. Unfortunately, the resistance to air flow presented by the filter element can require doubling the electric motor size to maintain a desired level of airflow. Further, HEPA-compliant filter elements are expensive, and can represent a substantial portion of the sale price of a HEPA-compliant filter-fan unit. While such filter-fan units can condition the air by removing large particles, particulate matter small enough to pass through the filter element is not removed, including bacteria, for example.
It is also known in the art to produce an air flow using electro-kinetic techniques, by which electrical power is directly converted into a flow of air without mechanically moving components. One such system is described in U.S. Pat. No. 4,789,801 to Lee (1988), depicted herein in simplified form as FIGS. 1A and 1B. Lee""s system 10 includes an array of small area (xe2x80x9cminisectionalxe2x80x9d) electrodes 20 that are spaced-apart symmetrically from an array of larger area (xe2x80x9cmaxisectionalxe2x80x9d) electrodes 30. The positive terminal of a pulse generator 40 that outputs a train of high voltage pulses (e.g., 0 to perhaps +5 KV) is coupled to the minisectional array, and the negative pulse generator terminal is coupled to the maxisectional array.
The high voltage pulses ionize the air between the arrays, and an air flow 50 from the minisectional array toward the maxisectional array results, without requiring any moving parts. Particulate matter 60 in the air is entrained within the airflow 50 and also moves towards the maxisectional electrodes 30. Much of the particulate matter is electrostatically attracted to the surface of the maxisectional electrode array, where it remains, thus conditioning the flow of air exiting system 10. Further, the high voltage field present between the electrode arrays can release ozone into the ambient environment, which appears to destroy or at least alter whatever is entrained in the airflow, including for example, bacteria.
In the embodiment of FIG. 1A, minisectional electrodes 20 are circular in cross-section, having a diameter of about 0.003xe2x80x3 (0.08 mm), whereas the maxisectional electrodes 30 are substantially larger in area and define a xe2x80x9cteardropxe2x80x9d shape in cross-section. The ratio of cross-sectional radii of curvature between the maxisectional and minisectional electrodes, from Lee""s figures, appears to exceed 10:1. As shown in FIG. 1A herein, the bulbous front surfaces of the maxisectional electrodes face the minisectional electrodes, and the somewhat sharp trailing edges face the exit direction of the air flow. The xe2x80x9csharpenedxe2x80x9d trailing edges on the maxisectional electrodes apparently promote good electrostatic attachment of particular matter entrained in the airflow. Lee does not disclose how the teardrop shaped maxisectional electrodes are fabricated, but presumably it is produced using a relatively expensive mold-casting or an extrusion process.
In another embodiment shown herein as FIG. 1B, Lee""s maxisectional sectional electrodes 30 are symmetrical and elongated in cross-section. The elongated trailing edges on the maxisectional electrodes provide increased area upon which particulate matter entrained in the airflow can attach. Lee states that precipitation efficiency and desired reduction of anion release into the environment can result from including a passive third array of electrodes 70. Understandably, increasing efficiency by adding a third array of electrodes will contribute to the cost of manufacturing and maintaining the resultant system.
While the electrostatic techniques disclosed by Lee are advantageous over conventional electric fan-filter units, Lee""s maxisectional electrodes are relatively expensive to fabricate. Further, increased filter efficiency beyond what Lee""s embodiments can produce would be advantageous, especially without including a third array of electrodes.
The invention in applicants"" parent application provided a first and second electrode array configuration electro-kinetic air transporter-conditioner having improved efficiency over Lee-type systems, without requiring expensive production techniques to fabricate the electrodes. The condition also permitted user-selection of acceptable amounts of ozone to be generated.
The second array electrodes were intended to collect particulate matter and to be user-removable from the transporter-conditioner for regular cleaning to remove such matter from the electrode surfaces. The user must take care, however, to ensure that if the second array electrodes were cleaned with water, that the electrodes are thoroughly dried before reinsertion into the transporter-conditioner unit. If the unit were turned on while moisture from newly cleaned electrodes was allowed to pool within the unit, and moisture wicking could result in high voltage arcing from the first to the second electrode arrays, with possible damage to the unit.
The wire or wire-like electrodes in the first electrode array are less robust than the second array electrodes. (The terms xe2x80x9cwirexe2x80x9d and xe2x80x9cwire-likexe2x80x9d shall be used interchangeably herein to mean an electrode either made from a wire or, if thicker or stiffer than a wire, having the appearance of a wire.) In embodiments in which the first array electrodes were user-removable from the transporter-conditioner unit, care was required during cleaning to prevent excessive force from simply snapping the wire electrodes. But eventually the first array electrodes can accumulate a deposited layer or coating of fine ash-like material.
If this deposit is allowed to accumulate eventually efficiency of the conditioner-transporter will be degraded. Further, for reasons not entirely understood, such deposits can produce an audible oscillation that can be annoying to persons near the conditioner-transporter.
Thus there is a need for a mechanism by a conditioner-transporter unit can be protected against moisture pooling in the unit as a result of user cleaning. Further there is a need for a mechanism by which the wire electrodes in the first electrode array of a conditioner-transporter can be periodically cleaned. Preferably such cleaning mechanism should be straightforward to implement, should not require removal of the first array electrodes from the conditioner-transporter, and should be operable by a user on a periodic basis.
The present invention provides such a method and apparatus.
The present invention is directed to improvements with respect to state of art. In particular, the present invention includes an air cleaner having at least an emitter electrode and at least a collector electrode. An embodiment of the invention includes a bead or other object having a bore there through, with the emitter electrode provided through said bore of the bead or other object. A bead or object moving arm is provided in the air cleaner and is operatively associated with the bead or object, in order to move the bead or object relative to the emitter electrode in order to clean the emitter electrode.
In another aspect of the invention, the collector electrode is removable from the air-cleaner for cleaning and the bead or object moving arm is operatively associated with the collector electrode such as the collector electrode is removed from the air cleaner, the bead or object moving arm moves said bead or object in order to clear said emitter electrode.
In a further aspect of the invention, the air cleaner includes a housing with a top and a base, and wherein the collector electrode is movable through said top in order to be cleaned, and wherein as such collector electrode is removed from the top, said bead or object moving arm moves said bead or object towards the top in order to clean the emitter electrode.
In yet a further aspect of the invention, the emitter electrode has a bottom end stop on which said bead can rest when the bead is at the bottom of the emitter electrode. The bead moving arm is moveably mounted to the collector electrode such that with the bead or object resting on said bottom end stop, said bead or object moving arm can move past said bead or object and reposition under said bead or object in preparation for moving said bead or object to clean said emitter electrode.
In a further aspect of the invention, a method to clean an air-cleaner, which air cleaner has a housing with a top and base, and wherein said air cleaner includes a first electrode, a second electrode array, and a bead or object mounted on the first electrode and a bead or object moving arm mounted on the second electrode array, includes the steps of removing said second electrode array from the top of said housing, and simultaneously moving said bead or object along the first electrode as urged by the bead or object moving arm in order to clean said first electrode.
Other features and advantages of the invention will appear from the following description in which embodiments have been set forth in detail, in conjunction with the accompanying drawings.